<p>Same as <code>refWidth</code>. Useful when one needs to resize an element absolutely and relatively at the same time. Note that all percentages are relative to 100% of the referenced width.</p>

<pre><code>{ refWidth: 20, refWidth2: '-75%' } // resizes the element to 25% of the reference width (25% = 100% - 75%) plus extra 20 pixels</code></pre>
